Display screen or portion thereof with a transitional graphical user interface



The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

FIG. 1 is a front view of a display screen or portion thereof with a transitional graphical user interface showing a first image of the first embodiment of the new design;

FIG. 2 is a second image thereof;

FIG. 3 is a third image thereof;

FIG. 4 is a fourth image thereof;

FIG. 5 is a front view of a display screen or portion thereof with a transitional graphical user interface showing a first image of the second embodiment of the new design;

FIG. 6 is a second image thereof;

FIG. 7 is a third image thereof; and,

FIG. 8 is a fourth image thereof.

The appearance of the transitional graphical user interface transitions between the images shown in FIGS. 1-4 or FIGS. 5-8. The order, process, or period in which one image transitions to another forms no part of the claimed design. The broken lines shown in the drawing of a display screen or portion thereof form no part of the claimed design. 

CLAIM The ornamental design for a display screen or portion thereof with a transitional graphical user interface, as shown and described. 